About Measles, Mumps, & Rubella

Measles, mumps, and rubella (MMR) are discussed in tandem, as the MMR vaccine is a combination vaccine. Even when susceptibility to only one antigen is suspected, the MMR vaccine is always used.

Measles (rubeola)

Measles infection causes fever, runny nose, cough, and a rash all over the body. In more serious cases, ear infection, seizures, pneumonia, or brain damage can result.

Measles can cause serious health complications, such as pneumonia or encephalitis, and even death.

  • Children younger than 5 years of age and adults older than 20 years of age are at high risk of getting a serious case of measles. 
  • About 1 in 4 unvaccinated people in the U.S. who get measles will be hospitalized.
  • 1 out of every 1,000 people with measles will develop brain swelling (encephalitis).
  • 1 or 2 out of 1,000 people with measles will die, even with the best care.
  • Before the U.S. measles vaccination program started in 1963, about 3–4 million people in the U.S. got measles each year; 400–500 of them died, 48,000 were hospitalized, and 4,000 developed encephalitis because of measles.

2016 Measles cases

  • From January 2, 2016 to March 4, 2016, 2* people from 2 states in the U.S. (California and Texas) have been reported as having measles.

*Preliminary data reported to CDC’s National Center for Immunization and Respiratory Diseases, updated monthly.



Mumps infection starts out with flu-like symptoms including fever, headache, muscle aches, fatigue, and loss of appetite. Next, the salivary glands become swollen and painful. Mumps is a very contagious disease. Serious cases of mumps can result in deafness or fertility problems.


Rubella infection causes high fever and rash lasting a few days in most people. Rubella is much more serious for some people. Pregnant women who get rubella can pass it to the fetus, causing abortion, death, or preterm delivery. In newborns, rubella can cause a very serious disease called congenital rubella syndrome (CRS). CRS can cause:

• Deafness
• Serious defects of the eyes, heart, and brain
• Mental retardation
• Fetal and newborn growth problems.

After birth, an infant born with CRS is highly contagious and can spread rubella virus very easily. The best way to prevent this dangerous disease cycle is by getting the vaccine.

The primary objective of rubella immunization for women is to prevent fetal rubella infection and subsequent congenital rubella syndrome (CRS) in newborns. A child born with (CRS) may have a variety of congenital effects that depend upon the gestational age and developmental growth in progress at the time of infection. The syndrome causes more damage in early gestation, when more organ systems are developing. CRS defects can include sensorineural deafness, cataracts, microphthalmia, glaucoma, chorioretinitis, patent ductus arteriosus, peripheral pulmonary artery stenosis, atrial or ventricular septal defects, microcephaly, meningoencephalitis, mental retardation, and intrauterine and postnatal growth restriction.

After birth, an infant born with CRS sheds rubella virus heavily for a year or more. Consequently, a single case of CRS creates a potential danger of more maternal rubella cases and subsequent CRS. Clinicians should strive to inform parents and caretakers of the danger an infant with CRS can spread. Everyone involved with the CRS child’s care should understand that 1) these infants can spread rubella to susceptible children and adults, who may then transmit the virus to susceptible pregnant individuals; 2) the infant may shed rubella virus for a year or longer; and 3) it is the parents and caretakers who can prevent rubella disease transmission and further cases of CRS.

The MMR vaccine can be given to individuals who are allergic to eggs, as anaphylactic reactions from MMR-containing vaccines have been associated with other vaccine components.


Updated 3/9/16

This website is supported by an independent educational grant from Merck and an educational grant from Sanofi Pasteur U.S. 
ACOG does not allow companies to influence its programs, publications, or advocacy positions.